From 5b18a6bf44b93122ba6638d227153cd146a68973 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 13 Apr 2023 16:07:24 +0100 Subject: [PATCH] chardev: Allow setting file chardev input file on the command line MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Our 'file' chardev backend supports both "output from this chardev is written to a file" and "input from this chardev should be read from a file" (except on Windows). However, you can only set up the input file if you're using the QMP interface -- there is no command line syntax to do it. Add command line syntax to allow specifying an input file as well as an output file, using a new 'input-path' suboption. The specific use case I have is that I'd like to be able to feed fuzzer reproducer input into qtest without having to use '-qtest stdio' and put the input onto stdin. Being able to use a file chardev like this: -chardev file,id=repro,path=/dev/null,input-path=repro.txt -qtest chardev:repro means that stdio is free for use by gdb. Signed-off-by: Peter Maydell Message-Id: <20230413150724.404304-3-peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Marc-André Lureau [thuth: Replace "input-file=" typo with "input-path="] Signed-off-by: Thomas Huth --- chardev/char-file.c | 8 ++++++++ chardev/char.c | 3 +++ qemu-options.hx | 10 ++++++++-- 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/chardev/char-file.c b/chardev/char-file.c index 3a7b9caf6f..263e6da563 100644 --- a/chardev/char-file.c +++ b/chardev/char-file.c @@ -100,6 +100,7 @@ static void qemu_chr_parse_file_out(QemuOpts *opts, ChardevBackend *backend, Error **errp) { const char *path = qemu_opt_get(opts, "path"); + const char *inpath = qemu_opt_get(opts, "input-path"); ChardevFile *file; backend->type = CHARDEV_BACKEND_KIND_FILE; @@ -107,9 +108,16 @@ static void qemu_chr_parse_file_out(QemuOpts *opts, ChardevBackend *backend, error_setg(errp, "chardev: file: no filename given"); return; } +#ifdef _WIN32 + if (inpath) { + error_setg(errp, "chardev: file: input-path not supported on Windows"); + return; + } +#endif file = backend->u.file.data = g_new0(ChardevFile, 1); qemu_chr_parse_common(opts, qapi_ChardevFile_base(file)); file->out = g_strdup(path); + file->in = g_strdup(inpath); file->has_append = true; file->append = qemu_opt_get_bool(opts, "append", false); diff --git a/chardev/char.c b/chardev/char.c index e69390601f..661ad8176a 100644 --- a/chardev/char.c +++ b/chardev/char.c @@ -805,6 +805,9 @@ QemuOptsList qemu_chardev_opts = { },{ .name = "path", .type = QEMU_OPT_STRING, + },{ + .name = "input-path", + .type = QEMU_OPT_STRING, },{ .name = "host", .type = QEMU_OPT_STRING, diff --git a/qemu-options.hx b/qemu-options.hx index 59bdf67a2c..04c259157a 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3360,7 +3360,7 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" - "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" #ifdef _WIN32 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" @@ -3563,13 +3563,19 @@ The available backends are: Create a ring buffer with fixed size ``size``. size must be a power of two and defaults to ``64K``. -``-chardev file,id=id,path=path`` +``-chardev file,id=id,path=path[,input-path=input-path]`` Log all traffic received from the guest to a file. ``path`` specifies the path of the file to be opened. This file will be created if it does not already exist, and overwritten if it does. ``path`` is required. + If ``input-path`` is specified, this is the path of a second file + which will be used for input. If ``input-path`` is not specified, + no input will be available from the chardev. + + Note that ``input-path`` is not supported on Windows hosts. + ``-chardev pipe,id=id,path=path`` Create a two-way connection to the guest. The behaviour differs slightly between Windows hosts and other hosts: